Add debugging info for software compositor swap.

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
@@ skipping 1567 matching lines @@
   const size_t size_in_bytes = 4 * frame_size.GetArea();
 #ifdef OS_WIN
   scoped_ptr<base::SharedMemory> shared_memory(
       new base::SharedMemory(frame_data->handle, true,
                              host_->GetProcess()->GetHandle()));
 #else
   scoped_ptr<base::SharedMemory> shared_memory(
       new base::SharedMemory(frame_data->handle, true));
 #endif
 
-  if (!shared_memory->Map(size_in_bytes)) {
+  if (!shared_memory->Map(0)) {
+    DLOG(ERROR) << "Unable to map renderer memory.";
+    RecordAction(UserMetricsAction("BadMessageTerminate_RWHVA1"));
     host_->GetProcess()->ReceivedBadMessage();

[piman, 2013/10/23 00:10:15]

TBH this could fail if we're out of address space (or file descriptors - you may
want to add one more check, before this, on the handle) in the browser. I'm not
sure killing the renderer is the right thing to do in this case, but again, we
can't really do anything good either way :(

     return;
   }
+
+  if (shared_memory->mapped_size() < size_in_bytes) {
+    DLOG(ERROR) << "Shared memory too small for given rectangle";
+    RecordAction(UserMetricsAction("BadMessageTerminate_RWHVA2"));
+    host_->GetProcess()->ReceivedBadMessage();
+    return;
+  }
 
   if (last_swapped_surface_size_ != frame_size) {
     DLOG_IF(ERROR, damage_rect != gfx::Rect(frame_size))
         << "Expected full damage rect";
   }
   last_swapped_surface_size_ = frame_size;
   last_swapped_surface_scale_factor_ = frame_device_scale_factor;
 
   scoped_refptr<MemoryHolder> holder(new MemoryHolder(
       shared_memory.Pass(),
@@ skipping 1842 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content